Answer: To save myself some headache and heartbreak later. There is a lot that I do not need and do not want from the sci-fi companion for my setting.
- I don't need star-fighters, or a hundred different scales of ship
- I don't need armor and AP (especially since one typically cancels out the other in the SFC)
- I don't need mega-weapons that kill with a single hit, or a ton of weapon varieties.
- I don't need complicated rules for building a ship from the ground up since my players won't be focusing on that in-game.
This left me with a lot of streamlining.
- I have only one style of cannon for starships and it deals 3d6 damage (with no AP). This let me balance the Toughness of all of the starships that were roughly the same size. I might add different starship weapons later but they would have very different gameplay effects.
- I built a basic chart of starship statistics, then adjusted them by applying a template (passenger liner, courier, military, etc).
- Capital ships exist, but they don't have stats. They are like the Death Star, huge and bristling with weapons. A typical starship has no hope of taking on one of these behemoths so I use my own version of the Obstacle Rules for when heroes flee these things.
- By homogenizing the starship scale, I can allow heroes to modify their ships capabilities.
- I don't need rules for how many escape pods or crew quarters a ship has. It is assumed that the ship is designed adequately for its roll.
- Ships have a Toughness and Shields act as armor. I decided to keep things simple at first. I may add more shield maintenance rules if it seems that starship combat needs more things to do.
So here are my Staship Rules and designs. Sorry no art for this yet but It's still a work in progress.